Cardiac Histopathology Flashcards
Histological findings post MI
- Under 6hours
- 6-24 hours
- 1-4 days
- 5-10 days
- 1-2 weeks
- 2weeks+
- Under 6hours (normal histology, CK-MB also normal)
- 6-24 hours (loss of nuclei, homogenous cytoplasm, necrotic cell death).
- 1-4 days (infiltration of macrophages, peak troponin in at 24-48 hours)
- 5-10 days (removal of debris)
- 1-2 weeks (granulation tissue, new blood vessels, myofibroblasts, collagen synthesis)
- 2weeks+ (strengthening, decellularising scar tissue)
Complications of MI (4 main groups)
- Mechanical (e.g. CCF)
- Arrhythmias (e.g. VF)
- Pericardial (e.g. Peri-infarct associated pericarditis, pericardial effusion).
- Mural thrombus formation (can embolise)
5 main mechanical complications of MI
- Cardiogenic shock (contractile dysfunction due to loss of active muscle).
- CCF (due to ventr dysfunction and arrhythmias)
- LV infarct (papillary muscle dysfunction can lead to mitral regurg)
- Cardiac rupture (ventricular wall (haemopericardium), septum (left to right shunt), papillary muscle (mitral regurg)).
- Ventricular aneurysm (usually develops more than 1 month post MI).
main arrhythmic complication of MI
- VF (usually in first 24 hours, common cause of sudden death)
90% of patients develop an arrhythmia post MI.
Describe clinical features and the timespan of dressers syndrome.
Persistent low grade fever,
Chest pain (usually pleuritic)
Maybe pericardial effusion
Usually occurs 2-3 weeks post MI, but can be longer.
MI basic definition
Myocardial cell death due to prolonged ischaemia.
What is the difference between HFpEF and HFrEF
HFpEF- preserved ejection fraction. Diastolic heart failure. Ventricles do not relax properly to allow ventricular filling.
HFpRF- reduced ejection fraction. Systolic heart failure. Ventricles do not contract effectively to pump oxygenated blood around the body.
What are normal and abnormal ejection fraction percentages?
EF>75% indicates a hypertrophic cardiomyopathy.
Normal EF is usually 55-70%. However you can still have a normal ef, but HFpEF.
EF 40-55 indicates damage but may not be heart failure.
EF
Give 6 common causes of heart failure
- HTN
- Ischaemic heart disease
- Arrhythmias
- Valve disease
- Dilated cardiomyopathy
- Myocarditis
Give 6 clinical features of heart failure
Dyspnoea, orthopnoea, PND, wheeze, fatigue, RV failure, peripheral oedema
2 main causes of RV failure
LVF
Chronic severe pulmonary HTN
4 Heart failure investigations and findings?
BNP, CXR, ECG, echo
3 types of cardiomyopathy
Dilated (systolic dysfunction)
Hypertrophic (diastolic dysfunction)
Restrictive (diastolic dysfunction)
7 causes of dilated cardiomyopathy
Idiopathic, alcohol, peripartum, genetic, sarcoidosis, haemochromotosis, myocarditis
Causes of HCM
Genetic, glycogen storage diseases
Name 3 typical features of HCM
- Thick walled
- Heavy
- Hypercontractile
Histologically myocyte disarray.
3 causes of restrictive cardiomyopathy (connective tissues issues)
Sarcoidosis, amyloidosis, radiation induced fibrosis.
What is ARVC
Arrhythmogenic right ventricular cardiomyopathy
Myocyte loss with fibrofatty replacement typically affecting the RV.